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xmas2003 writes "I recently had cataract surgery with a Crystalens implant. With my cloudy yellowing (UV-filtering) natural lens removed, I see the world in a new light (more on that in a moment) as everything is brighter and colors are more vivid ... plus in focus.
As a typical Slashdot reader, I've been myopic since childhood, so it's wonderful not to have to wear glasses/contacts for distance. One interesting oddity is that I can now see ultraviolet light — it seems that there are a few people who have photoreceptors sensitive below 400nm into the UV spectrum. I've done some testing with a Black Light and UV filter to confirm this but would love to do more conclusive testing such as using a Monochromator — anyone in the Boulder, Colorado area have access to one? And any suggestions from Slashdot readers on how I can further explore this phenomenon? While I can't see dead people, I guess I have a 'superpower' ... although I'm not sure a middle-aged suburbanite dad should don purple tights and cape to become a crime-fighter!"

There are a few - VERY few - women who can see the edges of the ultraviolet wavelengths. No men, at all.

Have they tested that by dissecting women's eyeballs and measuring reception on the retina itself? Or are they asking the women what they see? Because the key difference here is the man in TFA has had his eyeballs surgically altered and his lenses replaced with a synthetic material. He doesn't have normal human eyes.

It isn't the lenses that detect ultravision. Nor, do the lenses pre-process photo stimuli. Nor, do the lenses send signals to the brain. It's the rods and cones at the back of the eyeball that detect, pre-process, then send signals along the optic nerve. Women who see anywhere near the ultraviolet have slightly different rods and cones at the back of the eye.

Yes, and the extra type of rods she is talking about is _between_ the red and blue kind.. so all it does is allow greater differentiation of already seen colours, i.e. absolutely nothing to do with UV at all. So 2-3% of the female population can see a crazy amount of shades of colour.

The blue cells _can_ detect into the UV range, in both men and women, however normally this is blocked by the natural lens.

Before you go off calling someone a liar, maybe you should check up on it first. Google "see ultravilot". I just replied to another of your messages. I have a replacement lens in one eye, so I see both ways (normal and altered vision).

These harmful effects are reduced by the lens, which absorbs UV and prevents it entering the eye. When the lens becomes opaque due to cataracts, it may be surgically removed, and can be replaced with an artificial lens. Even with the lens removed (a condition known as aphakia) the patient can still see, as the lens is only responsible for about 30% of the eyes' focusing power.

However, aphakic patients report that the process has an unusual side effect: they can see ultraviolet light. It is not normally visible because the lens blocks it. Some artificial lenses are also transparent to UV with the same effect. The receptors in the eye for blue light can actually see ultraviolet better than blue. Military intelligence is said to have used this talent in the second world war, recruiting aphakic observers to watch the coastline for German U-boats signalling to agents on the shore with UV lamps....

An illustration of how ultraviolet appears is provided by the Impressionist painter Claude Monet. Following cataract surgery in 1923, his colour palette changed significantly; after the operation he painted water lilies with more blue than before. This may be because after lens removal he could see ultraviolet light, which would have given a blue cast to the world.

JWSmythe wrote "... An illustration of how ultraviolet appears is provided by the Impressionist painter Claude Monet. Following cataract surgery in 1923, his colour palette changed significantly; after the operation he painted water lilies with more blue than before. This may be because after lens removal he could see ultraviolet light, which would have given a blue cast to the world."

But wouldn't the surgery also have given a blue cast to his paints? If so, he'd have chosen the same paints as he did b

This is absolutely correct. When photographed in ultraviolet, many flowers have color ques for insects to lead them to nectar (and obviously pollen) and are therefore much brighter and more vividly patterned in UV than the pigments in paint which may or may not have very narrow spectral content outside the visual spectrum we normally perceive.

These women just say "pfffrrt I can seen all colours, even ultraviolet!"

To which the researchers tried to explain how that's unlikely and would try to run some tests..

As suddenly the women says "Is it me, or is it getting hot inhere ?" while there's some 70s funkmusic that comes from her bra, which is bulging...

As the scientist tries to remain his posture, and tries to convince the woman with all spectrum vision he needs to investigate her claims.. she replies "Investigate this.... doctor..." while she pushes her boobs in his face and scientists view is blurred and limited to only a few spectrums... While making up his results out of shame to write down his actual personal findings.

Well, I can say that your assertion is flawed. I am a male. I can also see UV light with one eye. I had a congenital cataract (it was there from birth). When I was 19 (almost 20 years ago), the vision in one eye was 20/200 due to this. They cut the old lens out, and slid the new one in. At the time, we were advised to leave the bandage on for a week, so I did.

When I removed the bandage, I didn't see anything remarkable, other than I could see clearly. I also found that the lens was not easy to bend, so my focus in that eye has been fixed ever since.

Around Halloween time, I had my first experience under black lights. Well, it was more like extreme pain. The natural lens filters out the UV light. Being bathed in this bright UV light was roughly like looking straight into a very bright light.

Over the next 5 years or so, I became adjusted to being able to see UV. It's not a big deal. Sometimes I see the rough equivalent to visual feedback when looking at particular colors (blue, violet, and UV). Each eye is seeing a different color on the same object.

It's hard to explain what it looks like to most people though. A black light normally doesn't really look like anything. I see a bright blue light instead, only in one eye. Sometimes I close one eye, then alternate, so I can figure out what color the rest of you see. It's a very bright blue. Kind of like the difference between bottle of mustard, and a yellow caution sign. Well, except most of you would never have seen the yellow caution sign, so you won't have a frame of reference.

So is it the whole UV range? Hell if I know. Maybe. Maybe not. I've never been presented with a color wheel that covers UV colors to help determine the full range.

I always wear UV & polarized sunglasses when I'm outside. Light is really bright, especially in areas with a clear sky. Going from LA's smog to Florida's bright blue sky is like living in a house with 40W bulbs, and then replacing them all with 100W bulbs. Sunglasses are generally a good idea, but if I don't have them, I end up walking around with one eye open.

About 20 years later, I still see it. I was at a convention over the weekend, and they had blue backdrops behind the speakers, with black lights pointing at them. In one eye, it was a dull blue glow. In the other eye, it was a distracting bright blue light. So I watched most of the time with one eye open.:) It could have been worse. I would be blind in that eye by now.

I can see the edges of the UV spectrum and I'm male. It makes nightclubs very wierd places to be, but is quite helpful as it means I can actually see what people look like under the blacklight.
Of course that hasn't stopped me making some awful mistakes, but I blame that on the alcohol...

That would be tetrachromats [wikipedia.org], who can see richer colors (the fourth cone is somewhere between red and green) but not ultraviolet. It is however extremely rare. Totally different phenomenon AFAIK, and girls can have it due to having two X chromosomes. I've never heard of humans seeing into ultraviolet, but I suppose it is possible.

I think you are confusing this with being a tetrachromat (the opposite of being color blind), that is a trait that only women can. However; being a tetrachromat does not allow you to see a greater range of frequency (like into UV or IR) it just lets the normal range of colors be detected with a greater granularity.

Obviously, with his newfound UV-vision powers, he is ready to decode(or manipulate) the hidden coloration used by plants to attract bees...

As HiveLord, numberless swarms of eusocial attack insects will bend to his will! The crops of man shall be bounteous, or wither unpollinated, by his hand! His amazonian suicide warriors will throw themselves at all foes, laying down their lives that the Swarm's venom may find its target!

Obviously, with his new found UV-vision powers, he is ready to decode the hidden alien propaganda spread throughout our daily lives. Him and Roddy Piper should get together and finally put a stop to the ruling class of alien invaders!

Or he can see UV reflected by sunscreen lotions. That would be a good test to check if he can really see UV. I guess that the reflected wavelengths of different products might vary and he might not be able to see all of them, nevertheless a crowded beach should provide a good enough sample.

No they aren't safe. In the case of sunlight, eyes see it pretty strongly and the pupils contract to cut down the amount of light that strikes the retina thus protecting it. In case of UV, there is a chance he may not see a part of the spectrum so his pupils remain dilated letting in dangerous amounts of UV light. Same reason it is advised to never look at an eclipse with unprotected eyes.

For people who have had their lenses replaced, it's strongly advised to use UV filtering sunglasses. I'm one of them, for almost 20 years now, but only in one eye. I haven't actually checked, but I'm fairly sure that you are right. I can see UV, but I suspect my pupils don't contract, as I my night vision is maintained normally. Bright UV tends to hurt, so I normally react by closing that eye. At least that natura

That was my first thought, even with normal eyes UV isn't good for them, but if the OP has lost a layer of protection, then he needs to be even more careful about exposure as there's that much less eyeball protecting the nerves in the back of the eye.

Had it been IR sensitivity that would have been cool. But because UV unlike IR is higher energy than light in the visible spectrum you're much more likely to have eye problems in the future.

UV-A (400-315 nm) is OK for short-term exposure. Your pupils won't constrict like they do for visible light, so keep the intensity low. Plain old blacklights are 350-400nm with the peak at 365nm, plus a small peak in the very bottom of the visible spectrum (which is the purple glow).

UV-B (315-280 nm) will probably be invisible, and it will do bad things to your eyes, so please stick to very low intensities if you want to fool with this. Read up on the risks first.

UV-C (280-100 nm) is utterly hostile to biology - the upper atmosphere filters this range out so life never evolved mechanisms to deal with it. Actually, UV-C is hostile to damn near everything: just from my own experience, it bleaches everything, and most plastics will degrade and become brittle with mere hours of exposure. I've test-fired a 185nm lamp in the open for a few seconds (wearing goggles!) and even across the room you can instantly smell ozone forming as it starts ripping oxygen apart. Stay away!

You have the better of the replies so far (I've worked with UV devices daily, for 20 years). Many flowers have colors that can only be seen in the barely sub 400nm range, high into UVA, and just passed violet in the rainbow. This is where blacklights work as well. Staying above 315nm (and better above 350nm) presents much less risk, and is likely where his extended vision is anyway.

UVB exposure to the eyes should be avoided by everyone, and I don't recommend very long exposures of longer wave UVA either,

UV-C (280-100 nm) is utterly hostile to biology - the upper atmosphere filters this range out so life never evolved mechanisms to deal with it. Actually, UV-C is hostile to damn near everything: just from my own experience, it bleaches everything, and most plastics will degrade and become brittle with mere hours of exposure. I've test-fired a 185nm lamp in the open for a few seconds (wearing goggles!) and even across the room you can instantly smell ozone forming as it starts ripping oxygen apart. Stay away!

Brief glimpses won't hurt you at low power levels - this isn't a laser leaving a scorch track wherever it goes. The danger is in continuous exposure where your total absorbed dose accumulates to high levels.

365nm at a few watts is pretty low (but nonzero) risk. I work in a room with 300 watts of 365nm in the open every day and I don't really give it any thought when the lights click on.

Life has not evolved ways to deal with anything below about 300nm, which does not occur on the surface of the earth. 254nm is what they use for germicidal lamps. It kills bacteria by causing massive DNA damage... Consider that. Your skin is a little more resilient, but like sun exposure, it will result in sunburn if you blast yourself with a high dose, and over time it causes skin aging and eventually cancer. On your eyes you're running the risk of cataracts.

On the upside: your glasses almost certainly block 254nm. Pretty much everything does - the bulbs and any windows are made of fused quartz which is one of very few things that will pass 254nm. It also doesn't tend to reflect around as much as visible light. Even shiny aluminum surfaces will absorb most of it. Silver mirrors reflect it as long as it's first-surface reflections; glass in front will absorb it. So perhaps you're not getting that much exposure except when you reach under the lamp. You can measure it with a radiometer if you have one handy to see how much is really being reflected toward you.

My suggestion: I always use glasses regardless of exposure. For your skin, it kind of depends how you use it. If you flip the lights on for a minute to examine a sample and then turn them off, and you're only reaching under the light for a few seconds, it might be OK to accept (but not ignore!) the skin risks. If you're leaving samples to react under the lights for hours at a time, I'd suggest you go down to Tap Plastics and buy a sheet of polycarbonate - it's what they use in UV safety goggles, and it's completely opaque to UV. Attach it to the front of the bench, and just reach around when you have to prod your sample.

Fortunately we were all living underwater back then. Before the Oxygen Catastrophe we were really damn deep where there's no light at any wavelength. Even the green things stayed well under the surface until the ozone layer was established.

Nothing has ever lived in the presence of UVC. There are few absolutes in biology, and I certainly want my readers to consider the implications of that before they go experimenting with short wavelengths: life evolves to fill any niche it can, but it has never gone there, and neither should you.

Sorry; you do not have special UV-sensitive super-powers. So-called "black" lights are not, by any stretch of the imagination, UV-only. They have a filter on them that blocks most, but not all, visible light. They are called "black" lights because the UV causes appropriately fluorescent and phosphorescent materials to glow out of proportion to the visible light emitted by the bulb.

I have this "power" as well. Found it out when got my first set of UV blocking contact lenses. Prior to that, in sunlight, there would be an uncomfortable unfocused ghosting off of things. With the new lenses, it was gone. (Same lens material, brand, shape and power.) Unlike the photo of the black light in the link, black lights emit a ghostly violet blob of unfocusable light. It is very uncomfortable, like being shined in the face with a flashlight.

1. Check to see if this ability enhances your sight during low level light.
2. Check the boundaries of your abilities and record such data. Is there a certain amount of UV light you can and can not detect?
3. Use this ability for a stealth motion detector. If a robber can't see in the dark, but you can, this would be a advantage.
4. Use this ability to sneak in late at night to prevent people yelling at you!:p
5. During a Solar eclipse, TOTALLY watch it, with proper protection of course. You will be recieving a special view that few humans will ever experience.:3

Fluorescence will ruin your cover. Some biological things including your teeth will emit some greenish whitish light, paper will look the typical blue, and then there are some minerals that could be lying around that show fluorescence.

That would still make loads of stuff fluoresce unless you treated your entire house with special paint and hope the burglar isn't wearing any cotton and everybody keeps their mouth closed and hasn't washed their hair with certain brands of shampoo.

Raptors use UV vision. I read a couple of articles about birds floating in the sky, watching the ground for fresh rodent urine. The urine gives off a bright glow under UV, that is invisible in the "visible" light spectrum.

Raptors use UV vision. I read a couple of articles about birds floating in the sky, watching the ground for fresh rodent urine. The urine gives off a bright glow under UV, that is invisible in the "visible" light spectrum.

Back in WWII, when the medical treatment was much more primitive, elderly persons in England, who had vision partially restored by cataract surgery, were asked to watch for long wave UV covert signals, from off the coast vessels, as part of the war effort. This may be an urban legend -- it is unanswered on Snopes http://message.snopes.com/showthread.php?t=25056 [snopes.com], but I do recall reading about it as a child, I believe in a commentary written by Arthur C. Clarke. But the memory is vague, and who knows where Clarke might have learned of it. So as something vaguely remembered from a book half a century old, that may or may not exist, where the original author may or may not have had first hand knowledge,... well, by Internet standards, that's your proof right there!

I understand that the definitive text on ultraviolet astronomy was written about then by an astronomer who had also been through the operation.

For him astronomical objects with high UV emission were "naked eye objects". He could just look through the telescope eyepiece and zero in on interesting stuff, when others had to wait for the film to be developed.

Not as big a deal these days, with 'scopes aimed using semiconductor image sensors rather than naked eye. But may still be an advantage.

I dunno. I remember my great grandmother talking about sitting with her grandmother watching for this on the coast along with a naval officer to report. It could very well still be sealed, which considering how useful it would still be today, wouldn't surprise me at all.

My prescription glasses have the tint that goes from essentially clear to sunglasses depending on light. I've noticed if I look at black light with them on, they go kind of foggy, which I guess makes sense given that IIRC, it's actually ultraviolet light that makes the shift happens, which is also why they're less effective in cars. Anyone else have this effect?

In a completely unrelated topic, does anyone know of any (long term) UV phosphors? Perhaps the original poster could see glow in the dark "whatever" that most of us couldn't see. I'm not talking about short term florescence, bu

Superman can see even beyond the ultraviolet,
into the x-ray spectrum,
but only when he wants to.
Me, I've been trying like heck to shut off my ability to see blue,
primarily during Redskins/Cowboys football games,
but I haven't yet gotten it to work.
So I was thinking,
maybe the shorter wavelengths are what allow voluntary control.
Please let us know what you discover.

In related news for nerds,
here's a B movie about a guy who wanted to see more outside the normal-human spectrum,
but without the ability

One interesting oddity is that I can now see ultraviolet light — it seems that there are a few people who have photoreceptors sensitive below 400nm into the UV spectrum. I've done some testing with a Black Light and UV filter

1) Purchase a UV source and filter the heck out of it to output purely UV (no purple leakage). Ask a geologist or perhaps a scorpion exterminator, they'll know what to buy...

2) Visit astronomical telescope parties and offer your safety assistance... help walking down the mountain, help reading directions, help stepping off the road curb without tripping, just.. sighted help in general.

What to them is pitch black, to you, could be lit up like a searchlight, at least until your batteries die.

I see UV too,... at least technically and I don't believe it is that uncommon. In a college quantum physics lab we were looking at the emission spectrum of Hydrogen and the instructor was guiding us through various emission lines. He asked if we could see the purple line and then asked who could see the *other* purple line. I was the only one who could. He said he always asks that because every class there are one or two students (out of about 20) who could see just enough into the UV spectrum to see it. I don't recall which line it was but assume it was the Balmer n=6 line at 397nm.

I can't say this has been particularly more useful to me although I do think I see rainbows as 'wider' than most people with a much thicker "purple" band than others seem to see. Totally subjective and something I can't substantiate but I think I am more sensitive to sunlight as well.

I had cataract surgery earlier this year. My ophthalmologist told me that all modern replacement lenses filter out the UV to protect the eyes. However, the lenses do reflect light better than natural ones giving you a bit of a "cat's eye" effect. I like to tell people that I now have bionic eyes to go along with my augmented hearing. Does this make me a cyborg?

It could be Octarine [lspace.org]. Not sure if being able to do or at least see magic is considered superpower, but it could have interesting applications. In any case, is better than seeing infra-black.

Hey now, that's uncalled for. Sure, there are some around here who are still expecting the next Year of the Linux Desktop, but you can't let them speak for all of us!

But more seriously, I've had great vision more or less for my whole life. I don't think it's entirely genetic either (though my father has never needed glasses either), and I have always done a lot of reading/computer in my time as well. I just make sure to look away every few minutes and focus on something far away so my eyes don't adjust too

I'll ask around and see what I can find. Work has a lab to specifically measure human eye sensitivity across the spectrum, but unfortunately it's in Illinois. However, I'm wondering if you couldn't build a DIY spectrophotometer using a DVD as a diffraction grating, and see what your sensitivity/wavelength/intensity graph would be.

I thought all sunglasses had UV protection because the cheapest plastics aren't transparent to UV light. I was under the impression that UV filtration was easy because very few materials are UV transparent.

Any UV likely to reach your eye is non-ionizing. At the energies where it becomes potentially ionizing, it can't travel in air very far... so unless you have an short wavelength UV emitter up against your face there's hardly any danger there.

That may be true for non-ionizing radiation, such as visible and IR. However, because UV light is ionizing, the damage it does is CUMULATIVE. I.e., there is no threshold.

Sayeth wikipedia:

Most ultraviolet is classified as non-ionizing radiation. The higher energies of the ultraviolet spectrum from about 150 nm ('vacuum' ultraviolet) are ionizing, but this type of ultraviolet is not very penetrating and is blocked by air.

So, probably okay unless Ultraman wants to look at a strong source in a vaccum.

If it were me, I'd want the ability to switch the "shimmer" off: I'd keep both replacement eye lenses unfiltered, and then get a pair of glasses with a filter on one lens (which is also an idea more helpful for the submitter, since he already had the surgery).